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[Ni/57v 70/? Dec 8, 1925- J L KIMBALL PRESSURE CONTROL APPARATUS Filed April 19 Patented Dec. 8, 1925.

UNITED; STATE PATENT oFFlcE.

anus L. 'KI M ALL, or SALEM, MAssAoHusEms-Assmmn T0 RUGGLES-KLINGE- MANN MFG. 00., or SALEM, nassacnusm'rs, A coaronnrron or massacnusarms.

u PRESSURE-CONTROL APPARATUS.

7 Application filed A ril 19, 1923. 'Serial No. 633,232.

To all whom it may concern Be it known that I, JAMES L. KIMBALL,

a citizen of the United Statesfresiding at 9 Dearborn St., Salem, in the county of "Essex and State of Massachusetts, have in improved means for controlling dampers,"

rheostats, andvalvesror other pressure con trol devices, so that a, predetermined move ment of such devices will be effected for a given variation in pressure, and more particularly to provide an improved c1rcu1tinterrupting attachment for'completely and,

effectively breaking the circuit at predetermined stopping points regardless of the direction in which the motor is operating.

Another object of my invention is to provide means whereby a motor will operate over a greater or less pressure range according to adjustment between the limit of movement of the particular device which .the motor controls, and to provide means adapted to lrender tie motor inoperative at each of a plurality of predetermined cut-ofi' points "and provide means whereby the pressure setting is varied at eachof said cut-off points.

Oftentimes fluid pressure is not available, or the regulator must be located in a place Where it is subject to freezing. In such installations, it isdesirable to avoid theuse of water under pressure for operating the pressure-actuating device, such as a damper, rheostat or valve;

Compressed air or steam may be available for such purpose, but compressed air or steam is too elastic a fluid to be, used for i this purpose. A solid fluid body, like water, is required to give a positive movement to the pressure-actuating device and to prevent it from over travelling; i 1

Under such conditions I prefer: to use an electric motor and mypresent invention resides in improved means for controlling the stage, the pump wouldi' characteristic,

operation of said motor so as to prevent over travel or hunting action.

The general use of regulators of this class is to control sirable to operate such device over as vwide a pressure-operating range as possible, in

order to prevent hunting action. It is also in order not to operate the motor desirable, continuously, or in small increments of speed regulation, to establish "certain'fixed cut-ofi', or non-effective, speed-regulating points, at which the motor will be brought to rest and to maintain its non-effective setting for as great a load or pressure variation as seem's. desirable, and this feature should be adjustable; to" conform to varying load and pressure factors. Q I

It is claimed that'if the pressure changes slightly, it is'not desirable to change the speed setting for the loadv andthe' pressure may return to normal and if they do, a change inspeed regulation has been avoided which it was not necessary to make.

While it is desirable to have step action, instead of floating action, in the control of such pressure-regulating devices, it is not desirable to arrange such steps for ,uniform control, but to arrange such apparatus for varihble increments of control to meet any variable factors governing such performance. Take it in the case offthe control of a centrifugal pump, such pumps have a water is pumped until a certain speed is reached. Insuch cases, it is not desirable to have cut-off or stopping points until the speed of the pump has reached the pumping characteristic of the pump, and for this pumps,'blowers and dampers, 'and when used for this purpose,it is devariable pumping characteristic, in that no reason, the motorwhich controls the speed regulating device should the arranged with a longer operating period between cut-oil points while the speed of the pump is being brought up to this point.

It will be seen thatif cut-ofli points were arranged for the first s eed-building-up e unnecessarily operated without effecting any useful re ult. After the pump has reached its pum ing then it should be operate by steps, but such steps should not be uni- "formly spaced for the reason that the pumping will not be uniform, or in other words, the object to be attained is a uniform volume of water to be pumped for a-uniform variation in the discharge pressure of the pump, and not uniform action of the pump-controlling means. a

Take it in the case of damper control, the first closing movement of the damper used to regulate boiler-furnace draft has very little effect in checking the draft, the final closing movement-being the most effective and as uniform variation in steam pressure should produce uniform variation in draft and not uniform variation in damper movement, variable control to compensate for variable factors is found desirable.-

These variable factors arefound not only.

in pump and damper controlfbut also in forced and induced draft, fans, they also having a variable blowing characteristic .yvhich it is desirable to compensate for by variable action inthe controlling means.

In the drawings, Figure 1 shows a ver tical elevation of my invention, the pres;

sure chamber and the diaphragm being shown in section. Figure 2 shows the usual connection to a damper for controlling boiler draft. Figure 3 shows the connection to a balanced throttle valve for controlling steam-driven pumps, blowers and other apparatus. .Figure' 4 shows a connection to a rheostat for the control of motor driven apparatus.

Referring toFigure 1, a pressure chamber 1 has a pipe connection2 which is'operatively connected to'the pressure system. A diaphragm 3 is subjected on its under-'. side to the pressure of the system. 'The pressure, on the diaphragm 3 is counterbalanced by weights 4 supported from a lever 5. The lever 5 is pivoted at 6 andengages a pressure cap 7 at a point 8. The lowerface of the pressure cap is in contact with the diaphragm 3. .The above embodies a preferred pressure-responsive device used for actuating a contact switch for operating a motor 12. A preferred embodiment of a contacting switch. is shown mounted on the lever 5, in which 9 'is the. switch bracket or support. Contact points 10 and 11 are connected in the circuit of the motor 12 by means of alead wire 13,

for operation in one direction, and a lead wire 14 that is adapted to connect the motor 12- for operation in the reverse direction. One side of the main-line circuit 15 is connected direct to the motor 12 by means of a lead wire 16, and the other side of the circuit is connected to a double contact point v18 'bymeans of a lead wire 17.

- It will be understood that the motor switch shown is only illustrative as in some cases, where a large motor is found necessary, it will no doubt be found desirable will be seen that if the motor 12 is operling devices from the motor 12'can be varinetic switch.

I shall now describe the operation of the pressure-controlling devices, such as are shown in Figures 2, 3 and 4:, from the motor 12; The motor 12 operates a worm 19 which, in turn, operates a worm gear 20, and this gear, in turn, drives a spur gear 21, which engages a gear rack 22. It

ated in the direction indicated by the arrow 23, assuming that: the worm 19 is threadedright hand, the gear rack. 22 will be operated in an upward direction to close the damper or valve, or to operate therheostat; and that if the motor isoperate'd in. the direction indicated by arrow 24, the rack 22 will be operated in a downward direction to open"the damper or the valve, or to operate the rheostat in the reverse direction.

It should be understood that the arrangement for operating these pressure-controlously arranged and organizedv without departing from the scope of the invention.

, The rack 22 carries a circuit-interrupting attachment 25, which is pivoted to the ear rack 22 at a point 26, and is arrange to be adjusted to a greater or less angle, in relation to the gear rack 22, by means of a slot 27 formed at the upper end of the member 25. A clamping device" 28 holds the member 25 at whatever angle is found desirable. An arm 29 is pivotedto a stationary bearing 30. The left-handend of the arm 29 is connected to the lever 5 by means of a spiral spring 31. The opposite end of the arm 29 carries the double contact points 18; It will be understood-that contact points'18, as well as contact points 10 and 11, are properly insulated from the arm 29 and the switch bracket 9. The arm 29 is made fast to a shaft 32, and to the opposite end of'the shaft 32 is fastened a roll arm 33, carrying a roll 34, which engages the circuit-interrupting attachment which is adapted to connect the motor 1225 t e stepped -18 and thereby stop the motor.

" before the for a given variation the diaphragm 3.

I shall now ex lain how the motor is operated in accordance with variations in pressure in the pressure chamber 1. On an increase in pressure in' the chamber 1, the lever 5 is raised against the gravity force of the weights 4, which brings the contact point 10 into engagement with the contact point 18, effecting operation of the motor in one direction and when the pressure in the chamber 1- is decreased, the lever 5 is depressed, which brings the contact point 11 into engagement with the contact point 18 and eifectsoperation of the motor in the opposite direction,

I shall now explain how the circuit interrupting attachment breaksthe motor circuit at each of the steps 35-located on the member 25., Assuming an increase in pressure in pressure acting on in the chamber 1, the contact point 10 will engage the contact point 18, which will effect the operation of the motor in'the direction indicated by the arrow 23. This will result in an upward movement of the gear rack 22, and also of the member 25,. which is attached to the rack 22. As the member 25 starts to move upward, the next lower step 34 to cause the arm 29 to rock slightly about the shaft 32 in a clockwise direction, effecting a firmer engagement of the contact members 10 and 18." As the member 25 continues its upward movement, the spring 31 will cause the roll 34 to snap into place between the said step 35 and the step 1 35 immediately below it, effecting disengagement of the contact members 10 and Simultaneously with the snapping into place of the roll 34, the tension upon the spring 31 is released, causing a change inthe pressure setting of the pressure device, which means that a new pressure value must be set up contact can be again made between the contact members 18 and 10.

On a decrease in pressure in thevch'amv her 1, contact is made between the contact members 18 and 11, which effects operation of the motor in the direction indicated by the arrow 24-. This will result in a downward movement of the gear rack 22 and the step member 25, which will place the roll 34 on a higher stepped position, thereby rocking the arm 29 to break the contactbetween the contact members 18 and 11 to stop the motor; and at the same time, an increased tension is laced on'the spring 81 to again change 1: epressure setting of the pressure-responsive device. As in the case of the upward movement-of the mem ber 25, the contact members will be caused to engage more firmly before contact is broken between them. ,1

It should be understood that the cut-off.

35 will at first engage the roll,

I of a plurality of predetermined pressure setbe so arranged as to effect a certain number I of revolutions of the motor between the first and the second cut off points on the first closing movement of a damper or other pressure-controlling device, and to decrease its effective operation a certain numberof revolutions between the second. and third cut-ofi points and so on. The cut-ofi' blocks are so spaced as to obtain any number of revolutions of the motor required between the cut-off points.

In accordance with the provisions of the patent statutes,'I have illustrated and described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and is capable of various modifications and that only such limitations shall be imposed as are indicated in the appended claims.

What is claimed is 1. In combination with a pressure-eon trolling device, an electric motor for controlling said device, a pressure-respqrfiive elementyand means actuated by said el ent for effecting the operation of said motor and a circuit-interrupting attachment controlled by the operation of themotor adapted to render the motor inoperativeat each of a plurality of predetermined pressure settings of the pressure responsive element and' 1 means to adjust said attachment to effect a greater or less pressure variation-between the limits of the operation of the pressurecontrolling device.

2. In combination with a pressure-controlling device, an electric motor for controlling said device, .a pressure-responsive element and a switch operated by said element foreffecting the operation of the motor, a circuit-interrupting attachment controlled by the operation of the motor adapted to render the motor inoperative at each tinge of the pressure responsive element and means to ad ust. said attachment to effect a greater or less pressure variation between the limits of movement of the pressure-controlling device.

3. In combination with a pressure-controlling device, an electric motor for controlling said. device, a pressure-responsive element operatively connected to a contact switch for effecting the operation of the motor, and a circuit breaker controlled by the operation ofthe motor adapted to open said switch at each of a plurality of predetermined pressure settings of the pressureresponsive element aifimeans to adjust said fi wi r aker "to efiect a greater vo rfless pressure variation acting onthe pressureresponsive element between the limitsof movement of the pressure controlling device.

- 4. In combination with a pressure-control lin device, an electric motor for controlling said device, a reversing switch having a neutral position in which it is not -efi'ective and two efiective positions for operating the motor in either direction, a pressure-responsive device for actuating said switch to either'of itssefli'eetive positions, a multiple stepped member operated bythe motor for'returning the switch to its neutral position at each stepped position, means to change the pressure setting of the pressure-responsive device. simultaneously with the return, of the switch to its neutral position, and means to adjust the degree of change in pressure setting, or the position of the multiple steps in relation to each other.

5. In combination with a pressure-controlling device, an electric motor for controlling device, and means for adjusting said circuit breaker as tothe duration of travel and the variation in pressure between the.

circuit interrupting points. 6. In a pressure system, a reversible electrio motor for controlling the pressure in 'the system having a range of operation between predetermined limits, means -controlled in accordance with the value of the pressure setting of-the said pressure for closing the circuit of the motor for operation in one or the opposite direction, means'whereby the value of the said pressure setting is varied in accordance with the point in the range of operation of'themotorat which the circuit of the motor is closed, and means controlled by the motor for opening the I for controlling the pressure in the system,

circuit of the motor, thereby to stop the .motor upon the 'motorucommencing to 7 In a pressure system, an electric motor a movable contact-member in circuit with the motor themovement of which is eontrolled in accordance with the pressure in the system, a contact member in circuit with the motor adapted to be engaged by the first-named i'iontact member to'efl'ect a clos ing of the motor circuit, andmeans for disengaging the contact members to effect the opening of the motor circuit upon the motor commencing to operate.

' 8. In a pressure system, an electric motor for controlling the pressure'in the system,

Lu eaese a movable contactmember in circuit with the motor, a scale beam controlled in ac-' cordance with the pressure in the system for-controlling the movement of the contact member, a contact member in circuit with the motor. adapted to be engaged by the firstnamed contact member to efieet a closing of the motor circuit, means'for disengaging the contact members to efl'ect the opening of the motor circuit upon the motor commencing to operate, and a spring conneetion between the second-named contact member and the scale beam.

9. In a pressure system, an electriemotor for controlling the pressure in the system, a movable contact member in circuit with the motor the movement of which is controlled in accordance with the pressure in the system, a contact member in circuit with the motor adapted to be engaged by the first-named contact member to effect a closing of the motor circuit, a compensating stepped cam-moved by the motor, and means connecting the steps of the cam to the second-named contact member to effeet a disengagement of the contact members and an opening of the motor circuit.

/ 10. In a pressure system, a reversible electricv motor for controlling the pressure in the systemytwo movable contact members in circuit with the motor for controlling the operation of the motor in opposite directions, a scale beam controlled in accordance with the pressure in the system for controlling the movement of the contact members in accordance with the pressure of the system, an arm having two contact members in circuit with the motor adapted respectively to be engaged by the scalebeani-controlled contact members to effect a closing of the motor circuit in one or the other direction, and means controlled by the motor for effecting movement of the arin at definite steps 1n the operation of the motor to separate the arm contact members from the scale-beam-controlled 'contaet members, whereby the motor circuit will be opened and the motor stopped at definite steps in the operation of the motor.

' 11. In combination, a pressure device, an electricmotor for controlling the pressure upon the cuit with the motor having an effective posi tion in which it-c'loses the motor circuit and an ineffective position, 5 means connecting the pressure device to the switch to cause the pressure device to actuate the switch to the effective position to .efiect a closing of the motor circuit, and a stepped cam moved by the motor for returning the switch to the neutral position.

12. In combination, a pressure device, an

ressure device, a switch in cir-.

electric motor for controlling the pressure upon the pressure device, a movable contaetmember in circuit with the motor, a

then effecting an abrupt motor, the pressure device being adapted to actuate the movable contact'member into engagement with the second contact member to effect a closing of the motor circuit, a stepped cam moved-by the motor, and

connections from the stepped cam to the contact members for first causing a firmer engagement of the contact members when e motor commences to operate, and for disengagement of the contact members to open the motor circuit. W

13. In combination, a pressure device, a

reversible electric motor for controlling the pressure upon the pressure device, a switch in circuit with-the motor the movement of which is controlledby the pressure device,

the said switch having a neutral position in which the motor circuit is open and two closed-circuit ositions for controlling the operation of t e motor and its direction of rotation, the pressure device being adapted to actuate the switch to the closed-circuit positions, and a stepped cam moved by the motor for returning the switch to its neutral position.

JAM s L. KIMBALL. 

